main21.c

//
// Created by ge on 2023/12/20.
//

#include <stdlib.h>
#include <stdio.h>


#define MAX 32767

typedef struct Graph {
    char *vexs;
    int **arcs;
    int vexNum;
    int arcNum;
} Graph;

typedef struct Edge {
    int start;
    int end;
    int weight;
} Edge;

Edge *initEdge(Graph *G) {
    Edge *edge = (Edge *) malloc(sizeof(Edge) * G->arcNum);
    int index = 0;
    for (int i = 0; i < G->vexNum; i++) {
        for (int j = i + 1; j < G->vexNum; j++) {
            if (G->arcs[i][j] != MAX) {
                edge[index].start = i;
                edge[index].end = j;
                edge[index].weight = G->arcs[i][j];
                index++;
            }
        }
    }
    return edge;
}

void sortEdge(Edge *edge, Graph *G) {
    Edge temp;
    for (int i = 0; i < G->arcNum - 1; i++) {
        for (int j = 0; j < G->arcNum - 1 - i; j++) {
            if (edge[j].weight > edge[j + 1].weight) {
                temp = edge[j];
                edge[j] = edge[j + 1];
                edge[j + 1] = temp;
            }
        }
    }
}

void kruskal(Graph *G) {
    int *connected = (int *) malloc(sizeof(int) * G->vexNum);
    for (int i = 0; i < G->vexNum; i++) {
        connected[i] = i;
    }
    Edge *edge = initEdge(G);
    sortEdge(edge, G);

    for (int i = 0; i < G->arcNum; i++) {
        int start = connected[edge[i].start];
        int end = connected[edge[i].end];
        if (start != end) {
            printf("v%c --> v%c weight = %d\n",G->vexs[edge[i].start],
                   G->vexs[edge[i].end],edge[i].weight);
            for (int j = 0; j < G->vexNum; j++) {
                if (connected[j] == end){
                    connected[j] = start;
                }
            }
        }
    }
}

Graph *initGraph(int vexNum) {
    Graph *G = (Graph *) malloc(sizeof(Graph));
    G->vexs = (char *) malloc(sizeof(char) * vexNum);
    G->arcs = (int **) malloc(sizeof(int *) * vexNum);
    for (int i = 0; i < vexNum; i++) {
        G->arcs[i] = (int *) malloc(sizeof(int) * vexNum);
    }

    G->vexNum = vexNum;
    G->arcNum = 0;
    return G;
}

void createGraph(Graph *G, char *vexs, int *arcs) {
    for (int i = 0; i < G->vexNum; i++) {
        G->vexs[i] = vexs[i];
        for (int j = 0; j < G->vexNum; j++) {
            G->arcs[i][j] = *(arcs + i * G->vexNum + j);
            if (G->arcs[i][j] != 0 && G->arcs[i][j] != MAX) {
                G->arcNum++;
            }
        }
    }
    G->arcNum /= 2;
}

void DFS(Graph *G, int *visited, int vexIndex) {
    printf("%c\t", G->vexs[vexIndex]);
    visited[vexIndex] = 1;
    for (int i = 0; i < G->vexNum; i++) {
        if (G->arcs[vexIndex][i] > 0 && G->arcs[vexIndex][i] != MAX && !visited[i]) {
            DFS(G, visited, i);
        }
    }
}

int main() {
    Graph *G = initGraph(6);
    int *visited = malloc(sizeof(int) * G->vexNum);
    for (int i = 0; i < G->vexNum; i++) {
        visited[i] = 0;
    }
    int arcs[6][6] = {
            0, 6, 1, 5, MAX, MAX,
            6, 0, 5, MAX, 3, MAX,
            1, 5, 0, 5, 6, 4,
            5, MAX, 5, 0, MAX, 2,
            MAX, 3, 6, MAX, 0, 6,
            MAX, MAX, 4, 2, 6, 0
    };
    createGraph(G, "123456", (int *) arcs);
    DFS(G, visited, 0);
    printf("\n");
    kruskal(G);
}